Optical Frequency Division Multiplexing (OFDM) is known as a modulation technique that allows efficient multiplexing i.e., combining of analogue or digital signals, transmission of the combined signals over a shared medium, and respective assigning of the combined signals to a multiplicity of users. Fast Fourier Transformation (FFT) are tools used ubiquitously in signal processing and signal analysis applications, including in OFDM. In recent years, the Discrete Wavelet Transform (DFT) is increasingly used to replace FFT in implementing OFDM, as the use of wavelet-based transforms overcomes some of the disadvantages associated with FFT-based OFDM, for example the creation of side lobes due to the use of rectangular windows.
Known multiwavelet-transform (MWT) or multiwavelet-based OFDM (MWT-OFDM) techniques are implemented by employing full-electronic or electro-optical techniques, both of which however require electronic signal processing. As known in the art, optical signal processing is much faster than electronic signal processing. Hence, the electronic processing in (for example) electro-optical techniques is sometimes referred to as “the electronic bottleneck”. Full-optical realizations of wavelet transforms are limited to the use of scalar wavelet transforms.
There is therefore a need for, and it would be advantageous to have an architecture that enables multiwavelet-based OFDM and, correspondingly, multiwavelet-based demultiplexing techniques that are implemented fully optically.
The description above is presented as a general overview of related art in this field and should not be construed as an admission that any of the information it contains constitutes prior art against the present patent application.